Phlebotomy and Specimen Collection Flashcards

A patient has small, fragile veins. Which needle gauge is most appropriate for venipuncture?

Answer: 23 gauge

A 23-gauge needle is the smallest standard venipuncture needle and is best suited for fragile or small veins to minimize trauma.

Which specimen type is required for a cortisol level that must reflect diurnal variation?

Answer: Timed blood draw with noted collection time

Cortisol levels fluctuate throughout the day, so the exact collection time must be documented to interpret results correctly.

When collecting a blood culture, what is the MOST important step to prevent contamination?

Answer: Use chlorhexidine or iodine and allow it to dry completely

Proper antiseptic preparation with chlorhexidine or iodine that is allowed to fully dry significantly reduces the risk of skin flora contaminating blood culture bottles.

A specimen labeled 'STAT' is received in the lab. What does this indicate?

Answer: Specimen requires immediate processing

STAT orders require immediate processing because the results are needed urgently for patient care decisions.

Which tube should be drawn FIRST when collecting a coagulation study along with other tests?

Answer: Sodium citrate (light blue)

Sodium citrate tubes for coagulation studies must be drawn before other additive tubes to prevent contamination that could alter clotting results.

A patient reports feeling faint during venipuncture. What is the FIRST action the medical assistant should take?

Answer: Remove the needle and apply pressure

The needle must be removed first to prevent injury if the patient loses consciousness or jerks away.

What is the purpose of inverting a blood collection tube after draw?

Answer: To mix the blood with the tube additive

Gentle inversion ensures the blood thoroughly mixes with the additive (anticoagulant, preservative, or clot activator) present in the tube.